Biosystematics of the monocotyledoneae—flavonoid patterns in leaves of the liliaceae

In a leaf survey of 168 species of the Liliaceae, most of the major flavonoid classes were found to be represented in the family. Flavonols occurred most frequently: quercetin and kaempferol were detected in 40% and 42% of the sample respectively, while the flavones luteolin and apigenin were present in only 24% and 20% of the sample. Methylated derivatives, i.e. isorhamnetin, diosmetin and tricin were rare. Procyanidins were present in 17 species, flavonoid sulphates in only one species and flavone C-glycosides in only three species. Anthraquinone pigments were identified in species of Aloe Asphodeline and Asphodelus. Three new flavonoid glycosides were characterised during the course of the survey: diosmetin 7-diglucoside in Colchicum byzanthinum and tricin 7-fructosylglucoside and tricin 7-rutinoside-4′-glucoside in Hyacinthus orientalis cv. ‘Quean of the Pinks’. On the basis of the flavonoid survey, the subfamilies of the Liliaceae may be grouped into those containing flavonols only, those with flavones only or those having both flavonols and flavones. Members of the related families: Amaryllidaceae (17 species), Agavaceae (1 species) and Xanthorrhoeaceae (1 species) contained only flavonols. The subfamilies Scilloideae, Asphodeloideae and Melanthioideae show the most chemical variation whilst the Wurmbaeoideae and Lilioideae are the most homogeneous groups. The tribe Scilleae is unusual in that both flavone- and flavonol-containing genera occur and a wide variety of flavonoid types are represented. A comparison of the leaf flavonoids of the Liliaceae with those found in families related to the grasses showed that all except two classes of flavonoid compound (5-methylated flavones and 5-deoxyflavonoids) found in the Juncaceae. Cyperaceae, Palmae and Gramineae are present in the Liliaceae thus supporting the view that all four families could have arisen from Liliaceae-like ancestors.     

Potent inhibition of microRNA in vivo without degradation

Chemically modified antisense oligonucleotides (ASOs) are widely used as a tool to functionalize microRNAs (miRNAs). Reduction of miRNA level after ASO inhibition is commonly reported to show efficacy. Whether this is the most relevant endpoint for measuring miRNA inhibition has not been adequately addressed in the field although it has important implications for evaluating miRNA targeting studies. Using a novel approach to quantitate miRNA levels in the presence of excess ASO, we have discovered that the outcome of miRNA inhibition can vary depending on the chemical modification of the ASO. Although some miRNA inhibitors cause a decrease in mature miRNA levels, we have identified a novel 2′-fluoro/2′-methoxyethyl modified ASO motif with dramatically improved in vivo potency which does not. These studies show there are multiple mechanisms of miRNA inhibition by ASOs and that evaluation of secondary endpoints is crucial for interpreting miRNA inhibition studies.     

“Trees Live on Soil and Sunshine!”- Coexistence of Scientific and Alternative Conception of Tree Assimilation

Successful learning is the integration of new knowledge into existing schemes, leading to an integrated and correct scientific conception. By contrast, the co-existence of scientific and alternative conceptions may indicate a fragmented knowledge profile. Every learner is unique and thus carries an individual set of preconceptions before classroom engagement due to prior experiences. Hence, instructors and teachers have to consider the heterogeneous knowledge profiles of their class when teaching. However, determinants of fragmented knowledge profiles are not well understood yet, which may hamper a development of adapted teaching schemes. We used a questionnaire-based approach to assess conceptual knowledge of tree assimilation and wood synthesis surveying 885 students of four educational levels: 6^th graders, 10^th graders, natural science freshmen and other academic studies freshmen. We analysed the influence of learner’s characteristics such as educational level, age and sex on the coexistence of scientific and alternative conceptions. Within all subsamples well-known alternative conceptions regarding tree assimilation and wood synthesis coexisted with correct scientific ones. For example, students describe trees to be living on “soil and sunshine”, representing scientific knowledge of photosynthesis mingled with an alternative conception of trees eating like animals. Fragmented knowledge profiles occurred in all subsamples, but our models showed that improved education and age foster knowledge integration. Sex had almost no influence on the existing scientific conceptions and evolution of knowledge integration. Consequently, complex biological issues such as tree assimilation and wood synthesis need specific support e.g. through repeated learning units in class- and seminar-rooms in order to help especially young students to handle and overcome common alternative conceptions and appropriately integrate scientific conceptions into their knowledge profile.     

Using Species Distribution Models to Predict Potential Landscape Restoration Effects on Puma Conservation

A mosaic of intact native and human-modified vegetation use can provide important habitat for top predators such as the puma (Puma concolor), avoiding negative effects on other species and ecological processes due to cascade trophic interactions. This study investigates the effects of restoration scenarios on the puma’s habitat suitability in the most developed Brazilian region (São Paulo State). Species Distribution Models incorporating restoration scenarios were developed using the species’ occurrence information to (1) map habitat suitability of pumas in São Paulo State, Southeast, Brazil; (2) test the relative contribution of environmental variables ecologically relevant to the species habitat suitability and (3) project the predicted habitat suitability to future native vegetation restoration scenarios. The Maximum Entropy algorithm was used (Test AUC of 0.84 ± 0.0228) based on seven environmental non-correlated variables and non-autocorrelated presence-only records (n = 342). The percentage of native vegetation (positive influence), elevation (positive influence) and density of roads (negative influence) were considered the most important environmental variables to the model. Model projections to restoration scenarios reflected the high positive relationship between pumas and native vegetation. These projections identified new high suitability areas for pumas (probability of presence >0.5) in highly deforested regions. High suitability areas were increased from 5.3% to 8.5% of the total State extension when the landscapes were restored for ≥ the minimum native vegetation cover rule (20%) established by the Brazilian Forest Code in private lands. This study highlights the importance of a landscape planning approach to improve the conservation outlook for pumas and other species, including not only the establishment and management of protected areas, but also the habitat restoration on private lands. Importantly, the results may inform environmental policies and land use planning in São Paulo State, Brazil.     

Image Corruption Detection in Diffusion Tensor Imaging for Post-Processing and Real-Time Monitoring

Due to the high sensitivity of diffusion tensor imaging (DTI) to physiological motion, clinical DTI scans often suffer a significant amount of artifacts. Tensor-fitting-based, post-processing outlier rejection is often used to reduce the influence of motion artifacts. Although it is an effective approach, when there are multiple corrupted data, this method may no longer correctly identify and reject the corrupted data. In this paper, we introduce a new criterion called “corrected Inter-Slice Intensity Discontinuity” (cISID) to detect motion-induced artifacts. We compared the performance of algorithms using cISID and other existing methods with regard to artifact detection. The experimental results show that the integration of cISID into fitting-based methods significantly improves the retrospective detection performance at post-processing analysis. The performance of the cISID criterion, if used alone, was inferior to the fitting-based methods, but cISID could effectively identify severely corrupted images with a rapid calculation time. In the second part of this paper, an outlier rejection scheme was implemented on a scanner for real-time monitoring of image quality and reacquisition of the corrupted data. The real-time monitoring, based on cISID and followed by post-processing, fitting-based outlier rejection, could provide a robust environment for routine DTI studies.     

An Excess of Deleterious Variants in VEGF-A Pathway Genes in Down-Syndrome-Associated Atrioventricular Septal Defects

About half of people with trisomy 21 have a congenital heart defect (CHD), whereas the remainder have a structurally normal heart, demonstrating that trisomy 21 is a significant risk factor but is not causal for abnormal heart development. Atrioventricular septal defects (AVSD) are the most commonly occurring heart defects in Down syndrome (DS), and ∼65% of all AVSD is associated with DS. We used a candidate-gene approach among individuals with DS and complete AVSD (cases = 141) and DS with no CHD (controls = 141) to determine whether rare genetic variants in genes involved in atrioventricular valvuloseptal morphogenesis contribute to AVSD in this sensitized population. We found a significant excess (p < 0.0001) of variants predicted to be deleterious in cases compared to controls. At the most stringent level of filtering, we found potentially damaging variants in nearly 20% of cases but fewer than 3% of controls. The variants with the highest probability of being damaging in cases only were found in six genes: COL6A1, COL6A2, CRELD1, FBLN2, FRZB, and GATA5. Several of the case-specific variants were recurrent in unrelated individuals, occurring in 10% of cases studied. No variants with an equal probability of being damaging were found in controls, demonstrating a highly specific association with AVSD. Of note, all of these genes are in the VEGF-A pathway, even though the candidate genes analyzed in this study represented numerous biochemical and developmental pathways, suggesting that rare variants in the VEGF-A pathway might contribute to the genetic underpinnings of AVSD in humans.